1. Field of the Invention
This invention relates generally to computer systems with graphical user interfaces and, more particularly, to control of computer activities with graphical user interface pointing devices.
2. Description of the Related Art
The interactive computer system operating environment, such as encountered by users of personal computers and the like, is characterized by efforts toward increasing ease of operation and convenience. An important contribution to making the operation of such computers easier and more convenient is the graphical user interface (GUI). A GUI provides a computer interface that is visually oriented and includes a variety of graphical artifacts displayed on a computer display that make the operation of the computer more intuitive and thereby can increase user efficiency.
A GUI operating system enables a user to move a computer display pointer by using a GUI pointing device such as a display mouse or track ball that is attached to the computer. Generating a control input by moving the mouse across a desktop or rolling the track ball in its cradle moves the pointer across the display in the same direction of movement, according to a response function of the pointing device. The relationship between pointing device control input and pointer response on the display screen is intuitive to the user. Many GUI systems permit multiple programs to be represented simultaneously on the computer display as different display windows. The boundaries of the windows can be adjusted or can be reduced to an icon representation. To activate a program, or to re-enter it, a user targets the display pointer within the desired program window or targets the display icon representing the program and presses a button of the display mouse or track ball device. Pressing the button, also referred to as "clicking" it, activates or re-enters the program. To activate a program without the GUI, a user would need to type the name of an executable file and provide it to the operating system. In this way, the keystrokes needed to activate or re-enter a program are eliminated or at least substantially reduced, making the computer easier and more convenient to use. The ability to point to a desired activity makes learning the operation of the computer easier and more convenient.
Additional improvements to program interaction through graphical user interface display pointer control are rapidly being achieved. For example, IBM Corporation has introduced a display pointer control feature called TrackPoint.TM. that includes a small, substantially rigid joystick-type actuator imbedded in the center of an otherwise conventional "QWERTY" computer keyboard. The TrackPoint control actuator is located between the G, H and B keys, between the hands of a typist at the home position, and is sufficiently short so that it does not interfere with normal typing on the keyboard. A computer user can apply lateral forces to the control actuator with his or her index finger to move the pointer around on the computer display, rather than using a display mouse. The keyboard provided with the TrackPoint feature includes a pair of click buttons below the middle of the space bar that duplicate the function of the display mouse buttons. These buttons are easily depressed with a thumb. In this way, the user's hands do not need to leave the keyboard to control the display pointer. The index finger and thumb of the same hand can simultaneously control the joystick-type actuator and either of the click buttons. A keyboard with such an integrated pointing device is especially desirable in a portable computer, known as a laptop or notebook computer, having a graphical user interface, where it can be inconvenient or difficult to connect and/or use a mouse or track ball with the computer to control display pointer movement. The IBM Corporation notebook computer is commonly referred to as a ThinkPad.TM. computer and includes a TrackPoint control actuator of the foregoing type.
The TrackPoint control actuator and associated click buttons significantly reduce the time required for a user to select windows, icons, text commands and other displayed features of a GUI over the conventional approach of manipulating a mouse or track ball physically separated from the keyboard. In addition, the TrackPoint control actuator and associated click buttons are particularly well suited for portable computers which are often used in airplanes, automobiles and other locations that do not have sufficient space for operation of a separate mouse or track ball.
The TrackPoint control actuator and associated click buttons which have heretofore been incorporated into commercially available computers sold by IBM Corporation are easy to operate insofar as performing a single click operation. However, there are instances where it is desirable to initiate the click operation from the TrackPoint control actuator itself. In this operation, the user positions the cursor or pointer over an object of interest on the computer display by applying forces with his or her index finger to the joystick-type actuator between the G, H and B keys. The user then depresses and releases the TrackPoint control actuator with his or her index finger in order to initiate a "click". In so doing, the user would then observe the GUI in order to visually determine whether the click had been recognized and accepted by the desired target. Clicking to select can be tedious with the aforementioned TrackPoint control actuator inasmuch as there is no feedback provided to the user that a given action has been accepted.